1. Field of the Invention
The present invention relates to a liquid container for storing a liquid such as ink fed to a liquid consumption apparatus such as an ink jet recording apparatus.
2. Description of the Related Art
As a representative example of a conventional liquid consumption apparatus, there is a liquid ejecting apparatus for ejecting liquid drops from an ejecting head and as a representative example of the liquid ejecting apparatus, there is an ink jet recording apparatus having an ink jet recording head for image recording. The ink jet recording apparatus makes comparatively little noise during printing and can form small dots of high density, so that in recent years, it is used for many types of print including color print.
As a liquid feed method for a liquid consumption apparatus represented by an ink jet recording apparatus, there is a method for feeding a liquid to a liquid consumption apparatus from a liquid container storing the liquid. Furthermore, in the liquid feed method by the liquid container, to enable a user to simply exchange the liquid container at the point of time when the liquid in the liquid container is consumed, the liquid container is generally structured as a cartridge removably mounted on the liquid consumption apparatus.
Generally, the ink jet recording apparatus has a carriage moving back and forth along the recording face of a recording medium having a loaded recording head for injecting ink drops and as an ink feed method from an ink cartridge to a recording head, there is a method with the ink cartridge mounted in the carriage for feeding ink from the ink cartridge moving back and forth together with the recording head to the recording head. Further, as another method, there is a method with the ink cartridge mounted in the case of the apparatus body for feeding ink from the ink cartridge to the recording head via an ink flow path made of a flexible-tube.
Meanwhile, when sending ink in the ink cartridge toward the recording head, there is a method for pressurizing ink in the ink cartridge by a pressurized fluid such as compressed air. By this method, ink can be stably fed against a fluid resistance generated between the ink cartridge and the recording head. As one method for pressurizing ink, there is a method for allowing compressed air introduced into the ink cartridge to make contact with ink and directly pressurizing the ink.
However, in the method for directly pressurizing ink in the ink cartridge by compressed air, a problem arises that when the pressurizing to ink is released, back-flowed compressed air is jetted from the pressurized fluid introducing port formed in the ink cartridge and in correspondence to it, ink leaks from the pressurized fluid introducing port.
An example of a countermeasure for responding to this problem is disclosed in Japanese Patent Laid-Open Publication No. 2002-307710 and here, a structure that ink leaking from the air introducing port flows back into the ink tank is proposed when it is pressurized again.